What occurred was not clear to her mind; but suddenly what appeared to be an open fireplace seemed to swing aside, leaving revealed a great black opening in the rock. To the lieutenant's snarl of command, one of the men released his grip of her arm, and lit a lantern which he took from a near-by shelf. The dim flicker of light penetrated a few feet into the dark hole, only serving to render the opening more grim and sinister. The girl shrank back, but the fellow still holding her tightened his grip. Cateras seemed to have regained his good humour, although the red welt across his face stood forth ugly in the flare. His thin lips smiled, and he bowed hat in hand, hatefully polite. "Go ahead with the light, Silva; not too fast, my man; the room beyond the _senor's_. Now, Merodez, release the girl." "Ah, so you can stand alone, _senorita_; that is well. Step in here, ahead of me, and follow the lantern--there is nothing to fear." She hesitated, and the smile on the Mexican's lips changed into a cruel grin. "Shall I make you again?" "No, _senor_." "Then you will do as I bid." "Yes, _senor_; I cannot resist." The passage was clean and dry, and seemed to lead directly back into the cliff. The faint light revealed the side walls and low roof, and the girl, again partially mistress of herself, recognised the nature of the rock to be limestone. Occasionally the floor exhibited evidences that human hands had been employed in levelling it, and there were marks along the side-walls to show where the passage had been widened; but the opening itself was originally a cave, through which water had run in long past ages--a cave wide enough to allow six men to walk abreast, but with an average height of about seven feet. For twenty feet it ran almost straight in; then they came to a sharp turn to the right, and entered a much narrower passage. The air was so pure and fresh, even after this turn was made, as to lead her to believe there must somewhere be another opening. The vague thought brought with it a throb of hope. Her view was limited to the slight radius illumined by the lantern, and even within that small area, her own shadow, and those of the three men, helped render everything indistinct. The side walls appeared to be of solid rock; she perceived no evidence of entrances into any side chamber, only that her eyes twice caught glimpses of what seemed like narrow slits at about the level of her head. She could not be certain as to their purpose, or ascertain exactly what they were, only they bore resemblance to an opening cleft in the rock, either for ventilation, or to permit of observation from without of some interior cell. Near each of these was a strangely shaped bracket of wood fastened in some manner to the side wall, apparently intended for the support of a light, as the ceiling above exhibited marks of smoke.